Description The (Eastern) Black Swallowtail (Papilio polyxenes) also called the American Swallowtail or Parsnip Swallowtail, is a butterfly found throughout much of North America. It is the state butterfly of Oklahoma. There is an extremely similar-appearing species, Papilio joanae that occurs in the Ozark Mountains region, but it appears to be closely related to Papilio machaon, rather than polyxenes. The Black Swallowtail has a wingspan of 8 to 11 cm (3.1 to 4.3 in). The upper surface of the wings is mostly black. On the inner edge of the hindwing is a black spot centered in larger orange spot. A male of this species has a yellow band near edge of wings; a female has row of yellow spots. The hindwing of the female has an iridescent blue band.